Fidelity Investments has hired Mike Plage, trader at Citigroup Investments in Hartford, Conn., as a trader in its liquid markets group. Plage traded investment-grade corporate bonds at Citigroup and left the firm at the start of the month, according to a former colleague. Steve Austin, spokesman for Fidelity, confirmed the hire but declined further comment. Plage could not be reached for additional comment and Citigroup officials did not provide additional information by press time.